Marshmallow oven



FIG. 1 is a side perspective view of a marshmallow oven in accordance with the present invention;

FIG. 2 is a front elevation thereof;

FIG. 3 is a rear elevation thereof;

FIG. 4 is a side elevation thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan thereof.

The broken lines depict environment and form no part of the claimed design. 

CLAIM The ornamental design for a marshmallow oven, as shown and described herein. 